Bacillus subtilis, isolated from the chili rhizosphere, capable of producing 3 mycolytic enzymes (chitinase, β-1,3-glucanase, and cellulase), was mutated by the chemical mutagen ethyl methane sulfonate (EMS). | Turkish Journal of Biology Research Article Turk J Biol (2013) 37: 323-328 © TÜBİTAK doi: Enhancement of mycolytic activity of an antagonistic Bacillus subtilis through ethyl methane sulfonate (EMS) mutagenesis Ashwini NARASIMHAN, Samantha SURESH, Deepak BIST, Srividya SHIVAKUMAR* Department of Microbiology, Center for PG Studies, Jain University, 18/3,9th Main, Jayanagar 3rd block, Bangalore, India Received: Accepted: Published Online: Printed: Abstract: Bacillus subtilis, isolated from the chili rhizosphere, capable of producing 3 mycolytic enzymes (chitinase, β-1,3-glucanase, and cellulase), was mutated by the chemical mutagen ethyl methane sulfonate (EMS). Mutants were screened based on their antifungal ability on dual plate assay against Colletotrichum gloeosporioides OGC1, the causal agent of anthracnose disease in fruit crops. EMS mutagenesis yielded 60 isolated mutants on NA plates, of which 3 (M3, M4, and M24) showed loss of antagonism against C. gloeosporioides OGC1 and 6 (M8, M21, M22, M57, M58, and M59) exhibited increased antagonism. The remaining mutants did not show any difference in their antagonistic property. In liquid culture, the mutants exhibited varied levels of the 3 enzymes. These mutants were studied for their mycolytic enzyme activities under shake flask conditions. Of all these mutants, M57 showed a 36-fold and increase in β-1,3-glucanase and cellulase activities, respectively, with a concomitant increase in hydrolytic activity, followed by M59, with a and increase in β-1,3-glucanase and cellulase activities, respectively, and a increase in hydrolytic activity as compared to the wild type B. subtilis strain. M24 exhibited a complete loss of β-1,3-glucanase and a decrease in chitinase, with a concomitant decrease in levels of hydrolytic activity with C. gloeosporioides mycelia as .
